Native pollinator specialist Robbin Thorp, emeritus professor of entomology at the University of California, Davis, said that "the large triangular pollen grains of this and other Onagraceae are held together in strings by viscin threads. You can see this on the anther above the bee’s head. This makes it a challenge for some bees to neatly pack this pollen, but helps pollen to get draped on the plant stigma."